甘肃省麦积区退耕还林生态效益评价

【目的】作为退耕还林工程有效性评价的重要环节,生态效益的评估也是新一轮工程实施的重要理论基础。本文旨在系统评价和研究退耕还林工程为麦积区带来的生态效益,研究成果可为当地退耕还林工程今后的生态研究提供理论依据。【方法】本文在调查研究的基础上,采用甘肃省麦积区自1999—2019年的退耕还林数据,参照《森林生态系统服务功能评估规范》以及《退耕还林工程生态效益监测评估技术与管理规范》,主要从水源涵养、固碳释氧、净化大气、保育土壤、生物多样性保护等5个方面对其所产生的生态效益做了评价。【结果】截止到2019年底,退耕还林工程为麦积区累积带来生态效益达1543816.03万元,且随着退耕年限的增长而持续增加,其中以涵养水源和固碳释氧贡献最大,分别占生态效益总价值的58.67%和30.69%,其次为保护生物多样性,保育土壤和净化大气,分别占总价值的9.88%、0.39%和0.37%。由于造林面积决定了退耕还林生态效益价值,因此,根据麦积区退耕还林不同植被恢复类型,产生的生态效益价值依次为荒山造林(776050.04万元)>退耕还林(732869.89万元)>封山育林(34876.32万元)。【结论】退耕还林工程为麦积区带来了显著的生态效益,尤其在涵养水源、遏制水土流失、固碳释氧等方面生态功能更为明显,为改善区域生态环境起到了有力推动作用。

Evaluation on Ecological Benefits of Returning Farmland to Forest in Maiji District of Gansu Province

【Objective】The evaluation on ecological benefits is not only an important part for assessing returning farmland to forest effectively,but also the theoretical basis for implementing a new round of project to return farmland to forests.This paper aims to evaluate and analysis the ecological benefits of returning farmland to forest in Maiji district,the result will be the reference for related ecological research.【Method】Based on the investigation and research,this paper uses the data of returning farmland to forest from 1999 to 2019 in Maiji District,Gansu Province.Refer to the“Forest Ecosystem Service Function Evaluation Specification”and“Returning Farmland to Forest Project Ecological Benefit Monitoring and Evaluation Technology and Management Specification”,the ecological benefits produced are mainly evaluated from five aspects:water conservation,carbon fixation and oxygen release,air purification,soil conservation,and biodiversity protection.【Result】By the end of 2019,the total value of forest ecological benefits reached 15438160.3 thousands yuan brought by the project of returning farmland to forest in Maiji District,and the total value continues to grow as the year of return farmland to forest increased,in which the protection of water conservation and carbon sequestration and oxygen production contributed the most,the proportions were 58.67%and 30.69%.Followed by the protection of biodiversity,soil and fertilizer conservation and air purification,accounting for 9.88%,0.39%and 0.37%of the total value,respectively.Since the area of afforestation determines the ecological benefit value of returning farmland to forest,therefore,according to the different vegetation restoration types of returning farmland to forest in Maiji area,the resulting ecological benefit value is in the order of afforestation on barren hills(7760500.4 thousands yuan)>returning farmland to forest(7328698.9 thousands yuan)>Closing the mountains for afforestation(348763.2 thousands yuan).【Conclusion】The project of returning farmland to forest has brought significant ecological benefits to the Maiji District,especially in terms of water conservation,soil erosion control,carbon sequestration and oxygen release,and other ecological functions,which have played a strong role in improving the regional ecological environment.